Grease gun



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A.` J. FARMER Oct, 23, 1923 GREASE GUN Filed Feb. 20. 1922 Fi e'.

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GREASE GUN.

4Application led February 20, ,41922. Serial No. 537,848.

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Be it known that I, ALBERT J. FARMER, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new andl useful Improvements in Grease Guns, of which the following is a specification, reference being had therein tothe accompanying drawings.

This invention relates to lubricating devices and more particularly to improvements in the class of such devices known as grease guns. 'lhe object of the invention is to provide a quick return movement of the ej ecting piston and simple means for releasing the power operating means from the piston rod. llt is also an object to provide certain other new and useful features in the construction -and arrangement of arts, all as hereinafter more fully describe.

W ith the above andother ends inview,the invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claims, reference being had to the acoornpanyino drawing in which Figure 1v is a si e elevation oi' a grease gun illustrative of the invention;

Fig@ is a longitudinal section through the same;

Fig. 3 is a transverse section upon the line 3-#3 ot Fig'. 2; and

Fig. 4:, a similar section substantially upon the line l-d of Fig. 2.

is shownin the drawing l indicates a barrel or cylinder within which is a piston 2 ot suitable construction having lateral pro'- jections 3 engaging longitudinal grooves in opposite sides of the cylinder wall to prevent rotation o the `piston therein as it 1s moved longitudinally therein by a' piston rod or stem i which is screw-threaded to engage a screw-threaded openingy in the piston. The lower end of the cylinder 1s closed by a suitable cap or closure 5 having a discharge nipple 6 into which is screwed a dischar e pipe 6 and the opposite end of thecyliner is closed by a head 7 providing a bearing Jfor the upper end or" the stem and through whic said4 stem extends. Power means is provided for turning the stem 4 comprising a worm wheel 8 seated in a recess in the head and held therein by .a ring 9 screw-threaded into the inner end ot the recess against the under side ot the worm wheel, said stem bein provided with a piston 10 which is formed rectangular-in cross-section to lit within' a rectangular opening in the wheel and an enlargement or collar 11 to engage the under side of the wheel, said stem being thus connected to the wheel-to turn therewith and to slide longitudinally therefrom uponendwise inward movement of the stem relative to the wheel. Within a lateral enlargement or chamber 1 2 of the head 7 is mounted a worm 13 in mesh with the worm wheel Sand an extended end or shaft 14C of the worm is provided with a crank 15 by means of which the worm may be turned to turn thel stem d through the i turningl movement of the wheel 8 and .thus move t e piston in the cylinder to torce the lubricant therefrom. Power applied to the crank 15 is multiplied by the worm and wheel and the motion is reduced, thereby putting a heavy pressure upon the lubricant below the piston to torce it from the cylinder. i

'ilhe above described construction oi? grease gun is the subject of my prior application erial Number 502,742 tiled by me Sept. 23, 1921 and forms no part of my present applicatlon with the. exception of the inanner of holding the worin wheel 8in place and detachably connecting the same to the rod or stem d, the present invention relatlng to the hereinafter described method and vconstruction for disconnecting the piston rod or stem e -from the worm drive so that the piston may be returned to the upper or inner end of the cylinder with a `comparatively quick return movement and direct turning of the stem.

lo move the stem i-longitudinally inward and thusdisconnect the formed portion 10 thereof from the worm wheel 8 and also to provide a hand-hold by means of which the stem may be rotated directly by the operator, a hand wheel 16 is mounted upon the upper end of the rod or stem 4i, which end rejects through an upward extension 17 of t e head- 7, said extension being formed hollow or with 'a chamber 18 to receivethe huh portion 19 oi the hand wheel and within which chamber is a spring 20v sleeved upon the stem between the bottom of the chamber and the inner ond oic the hub to exert a force ltending to normally move the rod t longitu-v the rod i moved inwardly against the'action ot' the spring 20 and out of engagement with the worm wheel 8 so that it maybe turned freely by means ot the hand wheel 16 and thus move the piston toward the upper end of the cylinder with a comparatively quick movement, a latch or spring catch is provided comprising a rod 21, mounted within a bore 22 extending inward from one side ot the head 7 with the inner end of the rod engaging the stem e and yieldingly `held 1n contact therewith by a spring 23 sleeved upon the rod within the bore between a collar 2lion the rod and a cap or plug 25 screwed into the outer end et the bore. A head 26 is provided onthe outer end of the rod which projects through the plug, by

' means et' which head the rod may be moved endwise against the action ot said` spring, and the stem 4t is provided with an annular groove 27 to be engaged by the inner end of the rod 21 when the stem is moved 1nwardly and hold said stem with its formed ortion 10 out of engagement with the worm wheel 8, at the same time permitting tree rotation of the stem by the hand wheel 16 for turning the screwstem or piston rod.

When the piston has been forced to the lower end ot its stroke to expel the lubricant trom the cylinder, by the turning ot the Screw stem 4 by means of the worm and Worm wheel, and it is desired to retract the piston to the upper or inner end oit its stroke .so that the cylinder may be reiilled with ilubricant, this retraction ot the piston may ,be ei'l'ected by a comparatively rapid rotation of the stem, by simply pressing inward upon the hand wheel 16 against the action of ythe spring 20, to disengage the stem from the worm drive, when the inner end or" the rod 21 will snap into the groove 27 in the stem and said stem will be held in the po,- sition 'to which it is moved. The operator may then turn the stem d direct, by means of the hand wheel and the piston will be quickly retracted.,y When the cylinder has been again iilled and it is desired to repeat the operation, the catch is released by pulling outward on the rod 21 against the action of the spring thereby releasing the stem l which will at once be moved end- Wise by the spring 20 to engage its formed portion 10 with the worm wheel 8 and operatively connect the stem to the worm drive.

The disconnection or connection of the stem to the worm drive is thus quickly and easily edected and a great saving in time in the operation ot the gun is effected by being able to retract the piston by a direct operation of the operating stem instead ot through the slow motion imparted thereto by the worm drive.

@bviously changes in the particular arrangement and construction of .parts may be made within the scope of the appended navieeo claims and l do not therefore limit myself to the particular formy or `construction shown.

Having thus fully described my invention, what I claim is 1. A device of the character described wherein a piston is reciprocated by a rotatable stem and wherein said stem is rotated at a low speed by driving means including a member slidably engaged by the stem, and means for turning the stem independently of said driving means, said means facilitating slidingsaid stem relative to said member for disengaging said stem from said member to permit. independent rotation ot the stem by said turning means.

Q. A. device of the character described wherein a piston is reciprocated by a rotatable stem and wherein said stem is rotated at a low speed by driving means including a member slidably engagedby the stem. means for turning the stem independently ot' said driving means, said means facilitating sliding' said stem relative to said member for disengaging said stem from said member io permit independent rotation of the stem by said turning means, and means for holding said stem in disengaged position.

3. A device of the character described wherein a piston is reciprocated by a rotatable stem and wherein said stem is rotated at a low speed by driving means including a wheel having a formed opening to receive a formed portion ot the stem and operatively connect the wheel and stem to turn together and permit a disconnection by an endwise movement ot the stem, and a hand wheel on the outer end of the stem Jfor turning the same independently ot said driving means. v

4." A device of the character described wherein a piston is reciprocated by a rotatable stem and wherein said stem is ro- I tated at a low speed by a worm drive including ,a worm wheel having a. termed opening to receive a formed portion oit the stem and cause said wheel and stem to turn together and to permit a disengagement by an endwise movement of said stem, means to yieldingly resist `the endwise movement of the stem in one direction, a hand wheel on the outer end of the stem to turn the stem independently ot' said worm drive, and means for locking said stem against the action of said yielding means.

5. ln a device of 'the character described, the combination with a cylinder, a piston in the cylinder, a screw stem for operating the piston, means for turning the stem at a low speed and with increased power including a wheel engaging the said stem, 'said stem being movable to disengage said steril from said wheel, a hand wheel on the outer end of the stem tor turning said stem independently ot said turning means, a spring to normally hold said stem engaged with said wheel of said turningl means, -andlocking means to hold thestem moved against the action of said spring.

6. In a device of the character described,

` a head on the cylinder formed with a chamber and th'rou h which said stem extends, wormdrive mec anism including a worm wheel sleeved upon the stem within the head and operatively connected to the stem to turn therewith, said stem being longitudinally movable to effect operative disengagement thereof from said Wheel, means carried by the head for holding said wheel and 'er mitting free rotation thereof, a hand w eel onthe outer end of the stem, a spring to normally. hold said stem in position to operativel operate loc ing member to hold said stem en age said wheel, and a spring out of operative engagement with said wheel, sai -stem being ormed with a circumferential groove to receive said locking member.'

7. In a grease gun, a piston, a screw driv# mg member, a piston operatm screw hav-4 ing a sl1d1n t 1n sald screw rivin memi ber to establish a' driving relation, sai screw having a reduced portion shiftable into said screw driving` member to temporarily-release said. screw relative to said driving member, and means to facilitate moving said screw.

8. A grease gun as called for in claim 7,-

and meansengageable with the reduced portion of said screw'to hold it in a releasedl position relative to said driving member.

\In testimony whereof I aiiix my signature in presence of two witnesses. l

ALBERT J. FARMER.' Witnesses:

ANNA M. Dona,` LEwIs E. FLANDERS. 

